There's a video on IGN of Matt playing the fishing game in Zelda: Twilight Princess and it looks like the cord is getting in his way a little bit while he's performing the reeling motion. The cable isn't very long, so it's something that you'll have to adjust to with the games that require both the Wii Remote and the Nunchuck controller and a wide range of motion. I haven't read anything about a longer cable or an extension, and I seriously doubt there will be one anytime near launch if we haven't heard about it yet.
Choose the "Matt Teaches Us to Fish" video and see what I mean...
Zelda Videos - IGN